Plasticized cellulose triacetate



Patented Sept. 2 195 22 PIIASTICIZED CELLULQSE TRIA CETATE pamyzc d John Kempton Aiken,

saleili i landliassienprs' to The Geigy' com an a-l Limited;fManchesterg England, a British com- 7 No Drawing. AppIicatio r,-February 20, 1948, Se

rial No. 9,968. 194% r v. 1 ;Glaim. (Cl

Thisinventiomelatesltoimprovementsimplas; l tic masses, such as foils, films, coating compositions, moulding compositions and the like.

me rm plastic;substancestare insolublenor at best, diflicultly and only slightly soluble in 5 most of the solvents .atlpresentlavailable. Fur.- ther. some of those liquids which do :have a sol v vent action may be unsuitable in respect of their volatility, toxicity or stability. Consequently the range of solvents and particularly of non-volatile 10 solvents. i. e. ,plasticisers), suitable for, the proauction of plastic" or fluid compositions-1mm such substances, is very limited.

Thus for example cellulose triacetate is potentially, an excellent material for plastic masses because of its heat and moisture-resistant properties: These,properties; are superiorqto' those of theagrades 10fcelluloseacetate customar ly ployedin thisart. mthertoa-howeverpits use has been restricted on account of its low solubility in volatile solvents, with the exception of halogencontaining toxic solventsaandeonxaccount: of ;;th. lack of suitable non-volatile solvents or plasticisers.

The object of this invention is cellulose triacetate plasticized .with-.=.r:ascyclicaacetaleof,other; following formula:

01 (Jr-CH2 S. 01 i o it The cyclic acetalsmfitherpresentdnvention may a be prepared by the condensation of chloral with a polyhydric alcohol, having hydroxyl groups on adjacent carbon atoms, in the presence of a strong condensing agent such as concentratedlsulphuric. 7 acid. Cyclic acetals soprepared and stilli containing a reactive group, such as hydroxylg, may be converted into yet further examples Ofl suitable compounds by appropriate chemical modifl cation, e. g. by esterification.

Thecyclicacetalsof-thepresant-invention proevidea groupof compounds among which thereares to befoundsolvents antvor plasticizers for:a wid'e range of-thermopl2tstic substancessuch as cellulose'es'ters-e. ge, cellulose-acetate and (:ell'iildse: acetobutyrate, cel'luloseethers, polyvinyl choride, co-polymers of vinyl *chlo'rldeandvinyl -acetate;- polyvinyl acetals, polystyrene, rubber and such synthetic elastomers as polymerised chlorobutadiene known commercially-:as neoprene,1 or-lthe range-*or alkylene polysulphides rknowmcommer niall'y'as *Thiokoh l In Great Britain February 24,

the present: invention may be dissolved in volatile solvents. to give solutions which may be emv played-as coating compositionsor foi the manu afacture of foils .ornfilms by known methods.

Alth ughlthesacetal groupin is.., o 1 1.alli'l,1m;- stableuparticularly to acid hydrolysissrthlaatri chloromethyl grqupypresent ;lIl --the---compounds" employed in the; present invention appears to exert a powerful stabilising influence, and renders the compounds highly resistant to hydrolysis by eith'en'acid for alkali,

The chlorine atoms not the trichloromethyl group also appear to be very resistant to removal by hydrolysis. Thus the compounds employed in. the presentdnvention show little or no: tendency to -decompose, with consequent formatioirrof hysm drogen chloride, under .o;moist conditions"or--ori"-" heating. For example the cyclic acetal of chloral with ethylene glycol i. e. trichloro methyl dioxolan or o-ona olblcec 1 C1 O-UH2 is stable'to boiling aqueous alkalies and ta, gboilg. ing concentrated hydrochloric acid and is only slowly decomposed by hot concentrated sulphuric acid v Theaamount of solubilising and/,or plasticisgjq'g ing agent incorporated withl the thermoplastic substance depends upon the purpose for which the compofiitiqn is to beaused. -As, is wel l, known amounts of ;plastici zeryexceeding 10% by weig of the thermoplastivsubstance are customarily employed. Amountsnexceeding 50% are most 3 in compositions where a low degree of combustibility is desirable.

The following table sets forth a number of the cyclic acetals of the present invention together Example 2 100 parts of polyvinyl chloride, 60 parts of trichlormethyldioxolan, and 10 parts lead silicate are mixed on hot rolls at about 125 C, and the h m their ner r ie Wlt so 8 of p opert and homogeneous pmass thereby obtained 1s moulded amples of thermoplastic substances with wh1ch u r at about 140 C. After cooling a light coloured each acetal may be Incorporated In tms table relatively non-inflammable moulding is obtained the symbol R. represents the radical Example 3 0013011 2 parts of cellulose triacetate (of combined acetic acid content 62.5%), 0.5 part of tri- O H: I

chlorethylidene glycerol, and 10 parts of cyclo- H1 pentanone are agitated together in an enclosed Table Compound General proprties 'Matenels for which solvent and/or plastioising action in c. an imvsl ms is shown Name Formula 7 0 CH2 Trlchloromethyldioxolan COIaGH l White crystalline solid, Cellulose acetate and triacetate, ethyl cellulose, poly- M. P. 42 0.3. P. 200 0. vinyl chloride and chloride/acetate. 0 CH2 Trichlorethylidene glycerol or OCH: Colourless viscous liquid Cellulose acetate, triacetate, and acetobutyrate and (-i-hydroxymethyl 2-tri- 33. P. 140 C. at 10 mm. ethyl cellulose. chloromethyldioxolen 1:3). 0 015GB OCIZH HO CH: 7

e-methyl 2-tn'chloromethyl- OCHz- Colourless liquid 33. P. Cellulose triacetate, polyvinyl chloride and chloride/ dioxolan 1:3. 208 C. acetate.

CClaCH 0 IE CH3 4-chloromethy1 2-trichloro- OOH: Oolourless liquid B. P. 129- Cellulose triacetate and acetobutyrate, ethyl cellulose, methyldioxolan 1:3. 133 C. at 14 mm. polyvinyl chloride and chloride/acetate, polyvinyl 001 611 acetals, polystyrene, rubber, and the synthetic elastomers marketed under the names Neoprene" O H and"Thiokol.

HaCl

Trichlorethylideneglyceryl R.O C O CH; Oolourless liquid B. P. 156- Cellulose triacetate and acetate.

acetate. 7 mm. I

Trichlorethylideneglyceryl 3.0 G 0 Colin White crystalline solid, Polyvinyl chloride and chloride/acetate.

benzoate. M. P. about C.

Bis (trlchlorethylideneglyc- R0 Colourless viscous liquid Cellulose acetate and trlacetate.

eryDIormal.

Bis(trichlorethylldeneglyc- B0 Highlyviscous undistillable Cellulose triacetate and acetate, polyvinyl chloride eryDtrichloroacetal. liquid. and chloride/acetate.

. CECCla Bis (trichlorethylidene glyc- C O 0 R Viscous undistillable liquid- Cellulose triaeetate (limited miscibility range).

eryDadipate.

.Bls(trichlorethylideneglyc- C O 0 R do 4.... Do,

eryl)sebacate.

C O 0 R The invention may be illustrated by the following examples in which all parts are parts by weight.

Example 1 vessel, 15 parts of tetrahydrofuran being gradually added during the process, which is continued 1 The 7 until solution is substantially complete. resulting lacquer, after clarification by filtration, centrifuging, or sedimentation as is customary in the art, yields clear, tough, glossy, moistureand heat-resistant films on air drying.

Example 4 i 2 parts of cellulose acetate (of combined acetic acid content 52-56%), 1 part of 4-chloromethyl .z-trichloromethyl dioxolan 1:3, and 25 parts of As in Example 4, except that 1 part of trichlorethylideneglyceryl acetate is substituted for 1 part of 4-chloromethyl Z-trichloromethyl dioxolan 1:3. A product similar to that of Example 4 is obtained.

Example 6 As in Example 3, except that 0.5 part of 4- chloromethyl 2-trichloromethyl dioxolan 1:3 is substituted for 0.5 part of trichlorethylidene glycerol. A product similar to that of Example 3 is obtained.

Example 7 As in Example 3, except that 0.5 part of his (trichlorethylideneglyceryl) formal is substituted for 0.5 part of trichlorethylidene glycerol. A product similar to that oi Example 3 is obtained.

Example 8 As in Example 3, except that 0.5 part bis (trlchlorethylideneglyceryl) trichloroacetal is substituted for 0.5 part of trichlorethylidene glycerol. A product similar to thatof Example 3 is obtained.

Example 9 As in Example 3, except that 0.5 part of his (trichlorethylideneglyceryl) adipate is substituted for 0.5 part of trichlorethylidene glycerol. A product similar to that of Example 3 is obtained.

Following the general procedure shown in the above examples cellulose acetate, polyvinyl chloride or other plastic materials such as a cellulose ester other than cellulose acetate, a mixed ester of cellulose, e. g. cellulose acetobutyrate, a cellulose ether e. g. ethyl cellulose, a co-polymer of vinyl chloride and vinyl acetate, a polyvinyl acetal, polystyrene, rubber, or a synthetic elastomer such as polymerised chlorobutadienc known commercially as neoprene, or the range of alkylene polysulphide polymers known comnercially as Thiokol may be plasticised with suitable amounts of any of the cyclic acetals, whose suitability therefor is indicated in the foregoing table.

We declare that what we claim is:

Plastic mass comprising cellulose acetate having a combined acetic acid content of about 62.5% and as a plasticizer a cyclic acetal of the following formula OCH:

CI CC C] O H H O CH:

HARRY J ONES". JOHN KEMPTON AIKEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Famulener Aug. 17, 1948 

